The invention relates to a method as recited in the preamble of claim 1. A non-limiting environment for practicing such method is a silicon factory for manufacturing digital electronic circuitry. Quantitative objectives for such an environment may be specified in terms of high yield expressed as a low percentage of malfunctioning products, a high output expressed in numbers of lots or batches or in broad wordings objects, that will be manufactured per unit of time, and furthermore a high utilization expressed as a percentage of time that the machines are active. Secondary objectives are to minimize total transit time for each particular product, and to finish each particular product at its target instant. The inventor has recognized that time-to-market has become an all-important parameter, that product lifetimes are shortening continually, and that the number of processing steps will increase steadily with the downsizing of layout details and the growing of chip complexity. In manufacturing this leads to a higher control complexity that may cause excessive and non-uniform delays, instabilities, and an unfortunate balance between inventory cost and income. Furthermore, a framework for coping with differentiated transfer times should be feasible.
In consequence, amongst other things, it is an objective of the present invention to provide manufacturing control management with an improved set of control tools that is applicable to a wide range of product mixes and factory sizes, and that would allow an acceptable user interface and intuitive and straightforward control concepts. Now therefore, according to one of its aspects, the invention is characterized according to the characterizing part of claim 1.
The invention also relates to a multistage processing environment arranged for executing a method as claimed in claim 1. Further advantageous aspects of the invention have been recited in dependent claims.